The present invention relates to a novel fluorine-containing, polymerizable monomer having a carbon-carbon double bond (hereinafter referred to as "a double bond") at one of its main molecular chain ends (hereinafter referred to as "the molecular chain ends") and a process for producing thereof. More in detail, the present invention relates to a novel fluorine-containing monomer having a double bond at one of its molecular chain ends and molecular weight of 300 to 1600, prepared by bringing a fluorine-containing telomer having a molecular weight of 200 to 1500 and an OH group at one of its molecular chain ends into esterification with acryloyl chloride or methacryloyl chloride.
Hitherto, there have been known numerous fluorine-containing, polymerizable monomers, and the polymers obtained from such a monomer have been broadly utilized as industrial material, materials for apparatus and instruments used in medical treatment and in electronics and the necessaries of life.
The present inventors have studied the utilization of fluorine-containing polymers comprising polyvinylidene fluoride for years as a material for apparatus and instruments used in medical treatment. For instance, although we have proposed a soft lining material for the denture base (refer to U.K. Patent Application GB No. 2027043A). U.K. Patent Application GB No. 2027043A discloses the soft lining material for lining the surface of the hard dental plate made of polymethyl methacrylate, which is contacted to the mucous membrane, with the soft fluoropolymer.
The demanded properties as a soft lining material for the dental plate are modulus of rigidity of 5 to 150 kg/cm.sup.2, water absorbance of less than 0.7%, adhesion strength of more than 250 kg/cm.sup.2, excellent compatibility to the mucous membrane, stability, etc. The lining material of the fluorine-containing polymer shows excellent properties as a soft lining material for the dental plate as compared with other lining material such as polyvinyl chloride, silicone rubber, etc. and accordingly the fluorine-containing polymer is extremely useful as a lining material for the dental plate.
However, since the operation of such a fluorine-containing polymer for equipping such a dental plate is not good, an improvement has been still demanded. In order to use the fluoropolymer of a high molecular weight as a surface material of the dental plate, which is contacted to the mucous membrane, it was found necessary to soften the fluoropolymer of a high molecular weight temporarily and thereafter to harden thereof again. The object of the present invention is to provide a novel fluorine-containing monomer solving the above-mentioned problems.